THE TECHNIQUE OF GOB-SIDE ENTRY RETAINING WITH ENTRY-IN PACKING ON ITS ORIGINAL POSITION IN FULLY-MECHANIZED COALFACE WITH TOP-COAL CAVING是什么意思_THE TECHNIQUE OF GOB-SIDE ENTRY RETAINING WITH ENTRY-IN PACKING ON ITS ORIGINAL POSITION IN FULLY-MECHANIZED COALFACE WITH TOP-COAL CAVING在线翻译_英语_读音_用法_例句